Gain and the threshold of three-dimensional quantum-box lasers

Asada, Masahiro; Miyamoto, Yasuyuki; Suematsu, Y.

doi:10.1109/jqe.1986.1073149

Cited by 1,099 publications

(439 citation statements)

References 20 publications

Supporting

Mentioning

428

Contrasting

Unclassified

Order By: Relevance

“…When semiconductor quantum-dots were first proposed, initial theoretical works suggested that the amplitude-phase coupling in these novel devices should be approximately zero, based on the atom-like energy states of quantum-dots [ASA86]. Atom lasers operating at their optical resonance do, in fact, exhibit α = 0.…”

Section: Charge-carrier-induced Susceptibility In Quantum-dot Lasersmentioning

confidence: 99%

Nonlinear and Nonequilibrium Dynamics of Quantum-Dot Optoelectronic Devices

Lingnau

2015

Springer Theses

View full text Add to dashboard Cite

In this thesis the dynamics and performance of optoelectronic devices based on semiconductor quantum-dots are investigated.In the first part, the dynamics of quantum-dot lasers under external perturbations is discussed. Using a microscopically based balance equation model that incorporates detailed charge-carrier scattering dynamics and the possibility to describe nonequilibrium between intra-band electronic states, the relaxation oscillations of the quantum-dot laser are investigated. Three qualitatively different dynamic regimes are identified in dependence of the scattering rates -the "constantreservoir" regime for slow scattering, the "overdamped" regime, and the "synchronized" regime for high scattering -characterized by a varying degree of nonequilibrium between the quantum-dot and reservoir states.Important differences to conventional lasers are found in the modulation response and the dynamics in optical injection and feedback setups. Common theoretical models and approaches used to describe these applications are shown to yield inaccurate predictions, especially in the "constant-reservoir" and "overdamped" dynamic regimes. An important consequence is that the amplitude-phase coupling in quantum-dot lasers, commonly described by the α-factor, differs from conventional descriptions due to the desynchronization of gain and refractive index. While the α-factor describes bifurcations of fixed points accurately, it fails in describing dynamic solutions and overestimates the extent of complex dynamics. The observed low sensitivity to optical perturbations in quantum-dot lasers can therefore be attributed partly to the charge-carrier nonequilibrium. Three quantum-dot laser models on different levels of sophistication are presented that can accurately describe the quantum-dot nonequilibrium dynamics.In the second part of the thesis, the performance of quantum-dot semiconductor optical amplifiers is investigated, and two types of applications unique to quantum-dots as active medium are discussed. The ground and excited states of the quantum-dots allow an ultra-broad-band amplification of optical data streams. Amplified signals on the ground-state frequencies are shown to generally exhibit higher quality than on the excited state, due to a lower sensitivity of the groundstate to carrier-density variations. Nevertheless the quantum-dot amplifier is found to allow effective amplification on both frequency ranges. Furthermore, a parameter range is identified that allows for a simultaneous amplification of data signals on the ground and excited state in a counter-propagating setup.The long microscopically polarization dephasing times in quantum-dots are found to enable quantum-coherent interactions on a macroscopic scale at room-temperature. By comparison with experiments, the occurrence of Rabi-oscillations by amplification of ultra-short pulses is demonstrated. Quantum-dot based devices could therefore be used for future applications based on quantum-coherent effects.

show abstract

Section: Charge-carrier-induced Susceptibility In Quantum-dot Lasersmentioning

confidence: 99%

Nonlinear and Nonequilibrium Dynamics of Quantum-Dot Optoelectronic Devices

Lingnau

2015

Springer Theses

View full text Add to dashboard Cite

show abstract

“…However, typically these sources only generate pulses with durations of greater than 1 picosecond (ps). It has been predicted for many years that replacing bulk and quantum wells (QWs) with quantum dots (QDs) as the active gain medium for semiconductor lasers should result in a number of enhancements in laser device performance, such as reduced threshold current density [3], lower sensitivity of the threshold current to temperature (T 0 ) [4], reduced chirp [5], much broad spectral gain bandwidths [6] and much faster carrier dynamics [7]. Recently, QD MLLs have received much attention [8] due to their inherent properties, leading to hopes of improved performance.…”

Section: Introductionmentioning

confidence: 99%

Ultra-high repetition rate InAs/InP quantum dot mode-locked lasers

Lü

Liu

Poole

et al. 2011

Optics Communications

View full text Add to dashboard Cite

“…First of all, QDs may be treated as a sort of laboratory to control and investigate many-body effects, resulting from the fact that a controlled number of carriers is confined in a small volume of semiconductor material. 1 Secondly, there are many device structures based on QDs that have improved parameters in comparison with other low-dimensional structures, 2,3 which is a consequence of their threedimensional quantum confinement of carriers and deltalike density of states.…”

Section: Introductionmentioning

confidence: 99%

On the modulation mechanisms in photoreflectance of an ensemble of self-assembled InAs∕GaAs quantum dots

Motyka

Sęk

Kudrawiec

et al. 2006

Journal of Applied Physics

View full text Add to dashboard Cite

We present the investigation of the modulation mechanisms in photoreflectance (PR) spectroscopy of an ensemble of self-assembled semiconductor quantum dots (QDs). In order to distinguish between possible factors contributing to the total modulation efficiency of QD transitions, a photoreflectance excitation experiment has been performed on an InAs∕GaAs quantum dot structure grown by solid-source molecular beam epitaxy. It has been observed that the intensity of PR features related to QDs changes in a function of the wavelength of the pumping laser, tuned from above-GaAs band gap down to below wetting layer ground state transition. Based on this dependence we have shown that most of the QD PR signal intensity originates from the modulation of the built-in electric field caused by carriers photogenerated in GaAs layers. We also conclude that the modulation of QD transitions related to a possible modification of the dot properties due to filling them with carriers is negligible in PR experiment on an ensemble of dots. An additional confirmation of the PR results has been obtained by using contactless electroreflectance (CER), demonstrating that the line shape of PR and CER QD resonances is almost identical in both spectra. Thus, the QD transitions can be analyzed by using the standard low field line shape functional form applicable in any electromodulation spectroscopy.

show abstract

Gain and the threshold of three-dimensional quantum-box lasers

Cited by 1,099 publications

References 20 publications

Nonlinear and Nonequilibrium Dynamics of Quantum-Dot Optoelectronic Devices

Nonlinear and Nonequilibrium Dynamics of Quantum-Dot Optoelectronic Devices

Ultra-high repetition rate InAs/InP quantum dot mode-locked lasers

On the modulation mechanisms in photoreflectance of an ensemble of self-assembled InAs∕GaAs quantum dots

Contact Info

Product

Resources

About